srsRAN 21.04

• Rename project from srsLTE to srsRAN
• Add initial 5G NSA support to srsUE (including x86-optimized FEC and PHY layer)
• Add PDCP discard support
• Add UL power control, measurement gaps and a new proportional fair scheduler to srsENB
• Extend GTP-U tunneling to support tunnel forwarding over S1
• Optimize many data structures, remove dynamic memory allocations in data plane
• Improved S1AP error handling and enhanced event reporting
• Update ASN.1 packing/unpacking, RRC to Rel 15.11, S1AP to Rel 16.1
• Update PCAP writer to use UDP framing
• Other bug-fixes and improved stability and performance in all parts

In addition to https://github.com/srsran/srsRAN/releases/tag/release_21_04_pre:

• Fixed E-RAB to DRB mapping, especially handling for E-RAB IDs > 12
• Fixed crash when UL info transfer is received for invalid S1AP ID
• Fixed compilation on some 32bit machines, e.g. RPi2 and above